This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 10-317867, filed Nov. 9, 1998, the entire contents of which are incorporated herein by reference.
The present invention relates to a filter-tipped cigarette and more particularly to an improvement of a plug wrapper for providing cigarettes that exhibit a small variations in ratio of air flowing into a cigarette through a filter (filter ventilation ratio: hereinafter referred to as xe2x80x9cVfxe2x80x9d).
A conventional filter-tipped cigarette is constituted by a tobacco rod and a filter that are connected by a so-called tip paper. The cigarette filter is formed by wrapping a wrapper paper around fibrous filter material, such as cellulose diacetate fibers, into a cylindrical shape. In recent years, in order to reduce the amount of a smoke component flowing into the mouth through a mouthpiece end of the filter, means is frequently used which causes air to flow in through the side surface of the filter, by combining a filter plug wrapper having an air permeability with a tip paper which is apertures by means of static electricity, a laser or the like. In such a filter with apertures, diluting air flows in through the peripheral portion of the filter into the mouth of a smoker while tobacco smoke is introduced through the central portion of the filter. Thus, the amount of the smoke component introduced into the mouth as a whole is reduced.
In the conventional cigarette described above, it has been confirmed that even where the filter plug wrapper and the tip paper are formed of the same material, large variations in the Vf value occurs. Since the Vf value is greatly correlated with the amount of the smoke component, these variations are not preferable.
Accordingly, an object of the present invention is to provide a filter-tipped cigarette that can suppress the variations of the Vf value and stably supply a reduced amount of a smoke component.
The applicant has disclosed in Jpn. Pat. Appln. KOKAI Publication No. 6-90728 (corresponding to U.S. Pat. No. 5,464,028) that in a filter-tipped cigarette comprising a tobacco rod and a filter connected by a tip paper having air-permeating holes (ventilation apertures), the variations of Vf values correlate with adhesion between the filter wrapper paper and the tip paper, irrespective of the air permeability of the materials, such as the filter wrapper paper, which is wrapped around the filter member. To improve the filter wrapper paper, the adhesion has been alleviated by embossing the filter wrapper paper which is wrapped around the filter member, so that the variations of the Vf values can be reduced.
Based on the above findings, the present inventors made further studies to more stabilize the Vf values. As a result, they discovered that the Vf values can be more stabilized by adhering an embossed filter wrapper paper to a tip paper only at projected portions of the embossment, accomplishing the present invention.
Thus, according to the present invention, there is provided a filter-tipped cigarette comprising: a tobacco rod including a tobacco filler and a tobacco wrapper wrapped around the tobacco filler; a filter including a filter member and a filter wrapper paper integrally wrapped around the filter member; and a tip paper sheet having a pluraliy of apertures arranged along a circumferential direction and connecting the tobacco rod and the filter, the filter wrapper paper having an embossment on substantially an entire surface thereof, and the filter wrapper paper and the tip paper sheet being adhered to each other selectively at projections of the embossment of filter wrapper paper.
In the present invention, the filter wrapper paper and the tip paper can be adhered except for a region where the plurality of apertures are formed. Further, in the present invention, it. is preferable that the embossment have a depth of 10 to 100 xcexcm, and the embossment have a pitch of 100 to 3000 xcexcm.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.